Acoustic headsets are known having earpieces on the ends of acoustic tubes contained in hingedly connected arms. Such frames tend to be expensive because of costs related to their hinge, and they do not bias the earpieces against the wearer's ears. Similar headsets are known (as in U.S. Pat. No. 2,142,407, issued Jan. 3, 1938 to Norton et al.) wherein a resilient frame has loops containing acoustic tubes. Such a frame cannot be molded, and assembly of the tube into tubular collars of the frame is inherently time-consuming, both of these considerations rendering such construction unduly expensive. Another such headset is disclosed in U.S. Pat. No. 3,730,290, issued May 1, 1973 to Scanlon, wherein acoustic tubes contained in rigid channel-shaped arms are connected by a resilient strip that provides bias to hold the earpieces against a wearer's ears. The frame of that headset can be molded of plastic material, promoting low cost. The design of the frame is intended to direct the earpieces at desired angles toward the wearer's ears. The resilient connecting strip between the rigid arms of that headset unfortunately is poorly adapted to resist stresses that develop in use which may cause the arms to become skewed, the earpieces then becoming misdirected. Moreover, the resilient connecting strip is poorly adapted to resist warping stresses that may occur when the headsets are stored, occasionally resulting in permanently deformed headsets.
Copending application Ser. No. 501,688 filed Aug. 29, 1974 by Sidney X Shore and Paul S. Martin, now U.S. Pat. No. 3,934,674 provides an acoustic headset having a frame for acoustic tubes, where resilience for biasing the earpieces against a wearer's ears is provided partly or wholly by arms of the frame. The Shore et al headset represents an improvement over the prior art, but the illustrative form of that invention involves objections which are discussed below.